Asahel k



KEZIAH A. VANDERBILT, OF'SA-ME PLACE.

PROCESS. OF OBTAINING cHRo [u M JAN-D c H'ROM |"u M ALLOYS.

srncrrrcn'rron forming'part of Letters Patent nd ieesoo, dated. March. 4,1890, Application filed March 80,18ti9. Serial No. 306,395. (No specimens.) v

To aZ Z whom it may concern: I I

Be it known that I, ASAHEL K. EATON, a

citizen of the United States, residing at Brook lyn,.in the county of. Kingsand State of New York, have invented certain new and; useful Improvements in the Process of Obtaining.

.Chromium and Chromium Alloys, of which the following is ,a specification.

possesses many Valuable qualities or properties; but it has hithertofbeen produced in such small quantities andat such great me 7 pense that its use in the arts has been ex,-

tremely limited. I have discovered a process or way of obtaining this mineral both ina pure state and in alloy with other metals at an expense whieh'is insignificant compared with that which. its production has hereto-v fore involved. I

My present invention is based upon or. in-" volves a discovery made by me" of certain chromites and the process of producing them,

- the complete process consisting, in general portant features therein.

terms, in first producing a chromite of adesired metallic base, then' reducing the chromite'to anlalloy, and then dissolving out or otherwise recovering themetal with which the chromium is combined. This proces'sI shall describe in detail and then indicate the parts which I' regard as the essential a'nd'im- As to the first step, which the production of ajchromite, I combine in equivalent be iron, copper, tin, orz inc.

proportions b'ichromate of potash and-the sulphate of the desired base, the best of which for practical purposes I have found to The bichromate ofpotash and one of the. sulphates above named in a finely-.di vided condition are mixed in equivalent proportions and placed in a fire-clay crucible or other suitable receptacleand exposed to a temperature gradually increasing until it reaches a white heat. By

this meansa reaction is'causcd to take place,

resulting in amut-ual decomposition of thetwo substances. The results lead me to ,believe that the sulph'uricacid of the sulphate coming sulphate of potash, while the chromic acid, released by this reaction and losing a portion of its oxygen, is immediately reduced bronze of great value. make .an exceedingly-hard metal which takes- I a high polish. bines with the potash of the bichromate, form- 'to chromous acid, which combines with the base and formsa chromite of that base. The sulphate of potash is readily removed by subsequent washing.

The seeoridstep-dahe reduction of the chromite-is eifected' as follows: A quantity of .the chromite is mixed with any suitable reducing agent to take up the 0xygen-such as The metal chromium, as 1s well known,

charcoal or substances like sugar, which will become charcoal-mud placed in a suitable retort orcr'ucible. Thecompound is then exposed toa temperature sufficiently high to reduce the two metals of the chromite as an alloy. I V The third stepthe' separation of the metallic -chr0mium=is efiected in any wellknown way, as bydissolvingout the baser metaL',

As some examples of this process I may citethe following: I have produced chronsAHnn K. EATON, OF BR OKLYN, NEW YORK, AssIGNoR OF 'ONE-HALF To mite of zinc by combining sulphate of zinc and bichromate of potash in the manner I above stated. This chromite, mixed with charcoal or equivalent reducing agent, I have heated until-the zinc and chromium wererun down in a metallic state asan alloy. I have then dissolved out the zinc with nitric acid, leaving the metallic chromium. In the same way I have produced alloys of chromium and copper, chromium and iron, chromium and tin, and others.

The difficulty of separating the chromium from the alloys will be greater or less, accord:

1 ing to the metal with which it isalloyed. To

obtain pure chromium, I prefertoproducethe alloy of zinc and chromium, as this is very easily reduced. Moreover the other al.- -loys named are products of great value'them-D,

selves. For exan1ple, by adding to the alloy of chromium and tin a further proportion of tin an alloy. resembling silver is produced, but which in every. respect is superior to silver; I v Y Chromium and copper makea chromium Chromium and iron In making the chromitesl mayemploy the chlorides of the metals instead of the sul- 5 i alloy.

A 1. I The process herein described o fobtainin'g metallic alloys of chromium, which consistsin first producinga chromite of the base ing said chromite to an alloy, and th'en sepav1o rating the baser metal from the chromium,

\of the desired metal and. then reducing such chromite to an alloy, as set forth.

.2. The process herein described of obtaining chromium; which consists in producing a chromite of a given metallic base, then reducii. The process herein described, which con;

' sists in heating a mixture of bichromate of sistsinheating a mixture of bichromatc of potash and the sulphate of zinc or its eqniva, lent to form a chromite, then heating the chromite and a reducing agent to obtain an 4. The process herein described, which con;

as set forth;

-, mium by reducing potash and-the sulphate ofzinc or. itsfequira lent to form a chromite, then'reducing the chromite with carbon to an alloy, and then removing the baser me'tal from the alloy,

leaving the. chromium.

5 The method or p'rocessof obtainin chro- 5 mium alloys by reducing the chromite ofa metallic base by heatan'd'a reducing agent-,-

6. 'The meth d or process of obtaining chrothechromiteof a metallic 

